It is highly advantageous to provide a bicycle rider the means for changing the height of the bicycle saddle while the bicycle is in motion. Having the saddle in a pre-set low position enables the rider to dismount, mount and start the bicycle more easily and with greater stability. Once started, the saddle can be raised to the optimum pedaling height for the rider. If the rider encounters a loose road surface, the saddle height can be quickly lowered to lower the center of gravity of the rider, to improve stability and allow the rider to use his feet to control the bicycle. If the saddle height must be changed while the bicycle is in motion, the rider should be able to make the change quickly, using only one hand and to a pre-set height. Changing saddle height also should be done without changing the saddle's orientation with respect to the plane of the bicycle frame.
U.S. Pat. Nos. 4,150,851; 3,861,740; 585,719; and 510,993 are illstrative of the attempts that have been made to provide such a device. U.S. Pat. Nos. 4,150,851 and 510,993 use a spring mechanism located within the saddle tube of the bicycle frame to effectuate height adjustments to the saddle. These devices require the frame and saddle to be adapted for their use and they are not easily available for cleaning and repair. U.S. Pat. No. 585,719 discloses a rack and pinion mechanism for adjusting handlebar and saddle height while U.S. Pat. No. 3,861,740 makes use of a hydraulic system in the bicycle frame's saddle holding tube.
Although all of the prior devices disclosed in these patents provide means for adjusting saddle height, they cannot be easily and economically retro-fitted to virtually any bicycle currently in use.